1. Field of the Invention
The present invention relates to an array substrate and method for repairing the same. More particularly, the present invention relates to a thin film transistor array substrate and method for repairing the same.
2. Description of the Related Art
To fit into our modern lifestyle, the size and weight of video or imaging equipment are decreasing at a phenomenal pace. Although the conventional cathode ray tube (CRT) displays still have some advantages, bulkiness and high operating power are some major factors that render its replacement by more versatile device inevitable. Nowadays, thin film transistor liquid crystal displays (TFT-LCD) have gradually become the mainstream display products in the market because of its high picture quality, high spatial utilization, lower power rating and radiation free operation.
A thin film transistor array substrate is a display device with a glass substrate. The glass substrate has a first metallic layer (a gate layer), a first dielectric layer (a gate insulating layer), a semiconductor layer, a second metallic layer (a source/drain layer) and a second dielectric layer (a passivation layer) formed thereon. Furthermore, a plurality of data lines, a plurality of scan lines, a plurality of common lines, a plurality of thin film transistors (each transistor having a gate, a semiconductor island structure and a source/drain) and a plurality of pixel electrodes are formed on the substrate. The gate connects electrically with the scan lines and the source/drain connects electrically with the data lines and the pixel electrodes. The scan lines and the common lines are part of the first metallic layer, for example. The semiconductor island structure is part of the semiconductor layer and the data lines are part of the second metallic layer. In addition, the scan lines are electrically isolated from their corresponding data lines through the first dielectric layer. Moreover, the second dielectric layer also covers the data lines.
In the process of fabricating the thin film transistor array substrate, dot defects or line defects are frequently produced. The most common conditions that result from line defects includes a broken common line, a short circuit between the common line and the data line, a broken scan line and a broken data line. When the aforementioned line defects occur in the thin film transistor array substrate, there will be a significant drop in the yield if the abnormal portion is not repaired. Hence, a systematic method for repairing such line defects is an important topic in the manufacturing of liquid crystal displays.